开发中经常用到查询指定表及其字段的信息，以下是我整理的SQL语句查询方法，供自己平时使用也提供给大家参考！
1.适用MS SQL SERVER:
1 SELECT 2 表名 = case when a.colorder=1 then d.name else '' end, 3 表说明 = case when a.colorder=1 then isnull(f.value,'') else '' end, 4 字段序号 = a.colorder, 5 字段名 = a.name, 6 标识 = case when COLUMNPROPERTY( a.id,a.name,'IsIdentity')=1 then '√'else '' end, 7 主键 = case when exists(SELECT 1 FROM sysobjects where xtype='PK' and parent_obj=a.id and name in ( 8 SELECT name FROM sysindexes WHERE indid in( 9 SELECT indid FROM sysindexkeys WHERE id = a.id AND colid=a.colid))) then '√' else '' end, 10 类型 = b.name, 11 占用字节数 = a.length, 12 长度 = COLUMNPROPERTY(a.id,a.name,'PRECISION'), 13 小数位数 = isnull(COLUMNPROPERTY(a.id,a.name,'Scale'),0), 14 允许空 = case when a.isnullable=1 then '√'else '' end, 15 默认值 = isnull(e.text,''), 16 字段说明 = isnull(g.[value],'') 17 FROM 18 syscolumns a 19 left join 20 systypes b 21 on 22 a.xusertype=b.xusertype 23 inner join 24 sysobjects d 25 on 26 a.id=d.id and d.xtype='U' and d.name<>'dtproperties' 27 left join 28 syscomments e 29 on 30 a.cdefault=e.id 31 left join 32 sys.extended_properties g 33 on 34 --a.id=g.id and a.colid=g.smallid 35 a.id=g.major_id and a.colid=g.Minor_id 36 left join 37 sys.extended_properties f 38 on 39 --d.id=f.id and f.smallid=0 40 d.id=f.major_id and f.Minor_id=0 41 where 42 d.name='表名' --如果只查询指定表,加上此条件 43 order by 44 a.id,a.colorder
2.适用ORACLE:
1 SELECT 2 USER_TAB_COLS.TABLE_NAME as 表名, 3 user_tab_comments.comments as 表备注, 4 USER_TAB_COLS.COLUMN_ID as 列序号, 5 user_col_comments.comments as 列备注, 6 USER_TAB_COLS.COLUMN_NAME as 列名 , 7 USER_TAB_COLS.DATA_TYPE as 数据类型, 8 USER_TAB_COLS.DATA_LENGTH as 长度, 9 USER_TAB_COLS.NULLABLE as 是否为空, 10 user_cons_columns.constraint_name as 约束名, 11 user_constraints.constraint_type as 主键 12 FROM USER_TAB_COLS inner join user_col_comments on 13 user_col_comments.TABLE_NAME=USER_TAB_COLS.TABLE_NAME 14 and user_col_comments.COLUMN_NAME=USER_TAB_COLS.COLUMN_NAME 15 INNER join user_cons_columns on user_cons_columns.table_name=USER_TAB_COLS.table_name 16 INNER join user_constraints on user_constraints.table_name=USER_TAB_COLS.table_name and user_constraints.constraint_name=user_cons_columns.constraint_name 17 inner join user_tab_comments on USER_TAB_COLS.TABLE_NAME=user_tab_comments.TABLE_NAME 18 WHERE USER_TAB_COLS.table_name='表名' 19 ORDER BY USER_TAB_COLS.TABLE_NAME
原文其它网址：http://www.zuowenjun.cn/post/2014/08/28/26.html
本文转自 梦在旅途 博客园博客，原文链接：http://www.cnblogs.com/zuowj/p/3940937.html ，如需转载请自行联系原作者
